The microprocessor has been catapulted into one of the most significant developments in the electronics field over the last decade. One of the reasons for this fast growth is the fact that technological advances into large scale integration have made the microprocessor the most effective, most reliable, simpliest, and least expensive way of accomplishing complex electronic functions today. It is not surprising, therefore, that the microprocessor, or in a larger sense, the microcomputer is dominating the technological development thinking for most equipment currently in the planning stages. The microcomputer is such a powerful performer that the vast majority of all possible applications probably could be served by any one of the dozens of different models available. Yet, for each application there probably is one microcomputer system which serves that purpose best. Despite occasional claims to the contrary, there is no such thing as a truly universal circuit, especially, not from the standpoint of cost-effectiveness. While one microcomputer system may come close to serving the bulk of all potential applications, it is likely that it will be over qualified for some, and under qualified for others. An over qualified system of course is not very cost effective. A microprocessor having CMOS transistors achieves the lowest possible power consumption.
Accordingly, it is an object of the present invention to provide a low cost, low power microprocessor having CMOS transistors and yet being capable of operating at speeds comparable to NMOS microprocessors.
Another object of the present invention is to provide a CMOS microprocessor having a common incrementer for a plurality of registers and using dual port storage cells in the registers which results in a reduction of chip area.